I seem to be losing the reference to my pointers here. I dont know why but I suspect its the pointer returned by fgets that messes this up. I was told a good way to read words from a file was to get the line then separate the words with strok, but how can I do this if my pointers inside words[i] keep dissapearing.
text
Natural Reader is
john make tame
Result Im getting.
array[0] = john
array[1] = e
array[2] =
array[3] = john
array[4] = make
array[5] = tame
int main(int argc, char *argv[]) {
FILE *file = fopen(argv[1], "r");
int ch;
int count = 0;
while ((ch = fgetc(file)) != EOF){
if (ch == '\n' || ch == ' ')
count ;
}
fseek(file, 0, SEEK_END);
size_t size = ftell(file);
fseek(file, 0, SEEK_SET);
char** words = calloc(count, size * sizeof(char*) 1 );
int i = 0;
int x = 0;
char ligne [250];
while (fgets(ligne, 80, file)) {
char* word;
word = strtok(ligne, " ,.-\n");
while (word != NULL) {
for (i = 0; i < 3; i ) {
words[x] = word;
word = strtok(NULL, " ,.-\n");
x ;
}
}
}
for (i = 0; i < count; i)
if (words[i] != 0){
printf("array[%d] = %s\n", i, words[i]);
}
free(words);
fclose(file);
return 0;
}
CodePudding user response:
strtok does not allocate any memory, it returns a pointer to a delimited string in the buffer.
therefore you need to allocate memory for the result if you want to keep the word between loop iterations
e.g.
word = strdup(strtok(ligne, " ,.-\n"));
CodePudding user response:
You could also hanle this by using a unique ligne
for each line read, so make it an array of strings like so:
char ligne[20][80]; // no need to make the string 250 since fgets limits it to 80
Then your while loop changes to:
int lno = 0;
while (fgets(ligne[lno], 80, file)) {
char *word;
word = strtok(ligne[lno], " ,.-\n");
while (word != NULL) {
words[x ] = word;
word = strtok(NULL, " ,.-\n");
}
lno ;
}
Adjust the first subscript as needed for the maximum size of the file, or dynamically allocate the line buffer during each iteration if you don't want such a low limit. You could also use getline
instead of fgets
, if your implementation supports it; it can handle the allocation for, though you then need to free the blocks when you are done.
If you are processing real-world prose, you might want to include other delimiters in your list, like colon, semicolon, exclamation point, and question mark.